The present invention relates to a drainage device used for body cavity drainage carried out in the examination or treatment of various kinds of cholangia sickness and the like.
In recent years, a percutaneous transphepatic cholangio-drainage (PTCD) has been widely used in diagnosis and treatment of cholangia sickness. With the wide use of PTCD, improvement of devices used therein and manual operation has been made, so that it has recently become customary to carry out drainage operation in which a puncture needle having a small diameter of 21G. (21 gauge: 0.813 mm OD) or 22G. (0.711 mm OD) is sticked and inserted into a bile duct through a right chest wall. Due to such drainage operation, the possibility of complication due to mannual operation has been reduced.
In the conventional method, however, there is the danger of the drainage tube bending in the abdominal cavity due to respiration or movement of a patient and dislodging from a bile duct. The dislodgement of the drainage tube in the abdominal cavity causes a very serious complication such as bile peritonitis. Such a situation becomes life threatening to the patient and requires an urgent drainage.
Further, there is a one step method such as a method wherein a thick puncture needle (for example 18G.: 1.219 mm OD) is initially sticked into the body cavity and a guide wire is inserted into the puncture needle, and then a large diameter dull needle on which a catheter is put is inserted into the body cavity along the guide wire after the puncture needle is pulled out by a conventional dull needle on which a catheter is put. However, in such a method operator of the dull needle sometimes feels a large resistance when inserting the dull needle since a tip of the dull needle has a dull taper (i.e., a tip of the dull needle is not to sharply pointed. Therefore, the above discussed one step method gives a great pain to a patient.
In the case of a two step method, (a thin puncture needle (for example 22G.) is initially sticked into the body cavity and a guide wire is inserted into the puncture needle, and then a dilation is gradually carried out by using two kinds of dull needles on which a catheter is put respectively, that is, by using a small diameter dull needle and a large diameter dull needle) by conventional dull needles. However, the two-step method becomes an operation which is time-consuming and complicated.
The present invention resolves the above-mentioned problems, and it is an object of the present invention to provide a drainage device capable of shortening the time required for inserting a drainage tube and preventing the drainage tube from dislodging from the bile duct.